Derived from the Latin Yessam Maatum, this expresion dates back centuries. Brutus was known to have exclaimed "Yes Maate" as he wiped away Caesar's blood from his dagger. Equally Henry VIII famously shouted "yes maate" when he learned he was to have a sixth stag do.

Nowadays the expression is commonly used, often unknowingly as they attempt the common/colloquial term "yes mate." Whilst similar on paper, their meanings do differ. With the double 'aa' signifying a greater emphasis/valididty/closer friendhip. Some say this double aa was due to Germanic influence altering the latin, however this is hotly disputed.